This invention relates to a highly efficient system and apparatus for supplying conditioned air to an interior space. The system utilizes two stage evaporative cooling to deliver conditioned air to living and work spaces, namely indirect and direct cooling stages. Such cooling is often identified by the acronym IDEC which stands for indirect/direct evaporative cooling. This invention seamlessly draws operating power from multiple AC and DC sources including a utility power grid and/or sustainable energy sources such as solar panels. A unique combination of indirect stage heat exchanger plate coatings and water distribution manifolds enhances the operation of the IDEC apparatus used in the system.
Other IDEC systems are described below. For example, U.S. Pat. No. 5,664,433 issued Sep. 9, 1997 to Davis Energy Group, Inc. (“Davis I”) describes an indirect-direct evaporative cooling apparatus with a single initial stream exiting a blower at the bottom of the apparatus that splits into primary and secondary streams that flow in a crossflow pattern through the indirect evaporative cooling stage. The primary air stream is directed horizontally through the indirect cooling stage and then through the direct cooling stage. The secondary air stream is directed vertically through the indirect cooling stage to evaporatively cool the air passing therethrough.
A pending application (Ser. No. 10737,823) assigned to the owners of U.S. Pat. No. 5,664,433, Davis Energy Group, Inc., (“Davis II”) notes several limitations of the Davis I patent allegedly cured by the IDEC apparatus disclosed in that application. More specifically, Davis II relocates the air handling fan to the top of the apparatus which reduces air flow and water handling problems apparently experienced with apparatus disclosed in Davis I. Davis II also utilizes a crossflow air pattern for the indirect heat exchanger stage that simplifies the construction of the apparatus. According to Davis II, the crossflow of air also increases the air path distance which, in turn, increases the efficiency of the unit. Davis II also discloses a simplified internal plate structure for the indirect cooling stage which enables the plates to interlock into an assembly, yet maintain spacing of air (dry) and water (wet) channels on opposite sides of the plates.
Another patent assigned to the Davis Energy Group, Inc. is U.S. Pat. No. 6,574,975 issued Jun. 10, 2003 (“Davis III”). It discloses a system for distribution of water in an evaporative cooling apparatus. More particularly, water which drips through evaporative cooling plates is collected in a sump and recycled to a water distribution manifold above the plates. The manifold disclosed in Davis III is little more than a horizontal perforated pipe which sprays on the underside of a semi-circular distribution surface that disperses the sprayed water over the top of the evaporative cooling media. (See reference numbers 36a, 60 of FIG. 2).
Other approaches to water distribution above evaporative cooling media are discussed in U.S. Pat. No. 5,192,464 issued Mar. 9, 1993. This patent discloses water distribution conduits 66 with discharge slots 68 cut in the top thereof (FIG. 5 and column 4, lines 46–6). The water exiting those slots dribbles down in a rather uncontrolled fashion over the evaporative cooling media. In U.S. Pat. No. 5,349,829 water distribution manifolds 152, 162 contain a plurability of downwardly directed spray nozzles 154, 164 which discharge onto the top surface of the evaporative cooling media (FIG. 1; column 4, lines 56–67). Yet another water distribution system for an evaporative cooler is illustrated in U.S. Pat. No. 4,427,607. In this patent outlets are located in the water distribution manifold so that they align with the wet side of evaporative cooling media. Conversely the dry side of the media is isolated from such outlets. (See FIG. 3 and column 3, lines 11–67).
Another supplier of IDEC units is AdobeAir, Inc. of Phoenix, Ariz. which sells such units under the MASTERCOOL® trademark. AdobeAir's web page (www.adobe.com) describes IDEC units with vertical fins which have water running therethrough to cool outside air passing over the outside of the fins
One approach to powering cooling equipment, more particularly a regular compressor driven air conditioner, is illustrated in U.S. Pat. No. 4,697,136 issued on Sep. 29, 1987. In this patent solar panels are connected in series as a source of direct current (DC). This DC solar power is supplemented or replaced with a commercial alternating current (AC) power source to run the air conditioner. These dissimilar (AC and DC) power sources are wired through an inverter system that provides flexible utilization of DC solar power alone, DC in combination with AC power or AC power alone. Selection of power sources is determined by a controller which switches power sources and inverters into and out of the power supply to the cooling equipment as illustrated in the only drawing in the patent (See also column 2, lines 29–64). U.S. Pat. No. 6,583,522 issued Jun. 24, 2003 describes a switching system that permits control of solar power by selective configuration of solar panels into series, parallel or series—parallel arrangements. This switching system permits control of voltage and amperage out of the solar panel. Another use of solar power in a cooling system in disclosed in U.S. Pat. No. 4,281,515 issued Aug. 4, 1981 to Energy Wise, Inc. of Lodi, Calif. This patent discloses use of solar heat (not power) linked to the absorption refrigeration cycle of a cooling system.